1. Field of the Invention
The present invention relates to a microcomputer including a function to output sound effects such as are used in a handy game, for example.
2. Description of the Related Art
With a conventional microcomputer including a sound output function, a series of parameter data stored in a memory of the microcomputer is read sequentially, a sound effects generating block is operated according to respective items of data which are read out, and sound effects are output.
Conventional microcomputers of this type includes a CPU (Central Processing Unit) and a memory for storing general data, connected to the CPU. The CPU is added with a circuit having a function to generate sound effects. This circuit with a sound effect generating function comprises a register for storing setting parameters for individual units of sound effects to be generated, a sound effect generating block for actually generating sounds by controlling output frequency, output time, and output level according to the parameters, a block for controlling the output of signals generated in the sound effect generating block, and so on.
To output and stop sound effects in a certain pattern, each time the output of sound effect corresponding to given parameter data ends, the next parameter data is read from the memory for data storage, this parameter data is stored in the parameter setting register, and sound effects corresponding to this parameter data are generated. Hereafter, this operation is repeated to eventually obtain a desired pattern of sound effects.
When a conventional microcomputer such as mentioned above is used, it is necessary to have all parameter data for sound effects to generate stored in the data storage memory, and therefore, a large memory area is occupied for this purpose.